Conventionally, among electronic equipment such as a television receiver, a recorder, and a tablet terminal, there is a communication device such as a contents transmission device (hereinafter, referred to as a source device) and a contents reception device (hereinafter, referred to as a sink device) that respectively transmits and receives contents files (hereinafter, referred to as contents) containing video information, audio information, or information combining them. Such a communication device transmits contents from a source device to a sink device through a wireless path such as a wireless local area network (LAN), so that the sink device reproduces the contents. When the reproduced contents are contents subjected to copyright protection, the contents are transmitted in a copyright protection system such as High-bandwidth Digital Content Protection (HDCP) and Digital Transmission Content Protection over Internet Protocol (DTCP-IP).
While the sink device reproduces contents after the source device transmits them to the sink device, the source device may receive operation from a user to confirm information. For example, when the source device is a tablet type information terminal, the user may confirm various kinds of information by operating a touch panel of the information terminal in his/her hand while viewing contents reproduced in the sink device. In the conventional technology described above, the sink device allows only reproduction of the contents. Thus, the user needs to confirm display of the source device also to confirm various kinds of information corresponding to the operation, which is inconvenient.